Power Table oldValue and newValue

I am using the onCellEdited extension function in a column with all none values.

	print "oldValue = ",oldValue
	print "newValue = ",newValue	

If I click on a cell but do not change anything it still changes the value to 0.0.

The oldValue is None and the newValue is 0.0.

How can I prevent 0.0 from being entered. I only want 0 if they enter it.

Thanks

Something like this should do the trick:

	if newValue == 0:
		newValue = None
	self.data = system.dataset.setValue(self.data, rowIndex, colIndex, newValue)

Edit: Sorry didn't read this part.

I only want 0 if they enter it.